The Immunologic Monitoring Laboratory (IML) will serve three of the five primary projects and two of the developmental projects of this SPORE application. This laboratory has two primary responsibilities: 1) It will perform the majority of assays proposed to assess the effects of treatment (e.g. with dendritic cell vaccines, biochemotherapy) on the number, phenotype, and function of melanoma antigen-specific T cells isolated from serial blood specimens, lymph nodes, and tumor biopsies. These assays will consist primarily of peptide- and tumor cell-based ELISPOT analyses, tetramer analyses, as well as assays of cytolytic activity, cytokine induction and proliferation. 2.) The IML will also be responsible for the studies proposed to evaluate the homing characteristics of cutaneous T cell lymphoma (CTCL) cells (Project 3) and those of lymphocytes obtained from the blood, lymph nodes, or tumor tissues of melanoma patients (Projects 4 and 5). These assays consist of extensive multi-parameter flow cytometry studies of adhesion molecule and chemokine receptor expression. The laboratory studies conducted by the IML will determine the extent to which various immune-based therapies immunize patients against melanoma antigens and the extent to which the results of surrogate assays of specific immune responses correlate with treatment outcome and other clinical parameters. They will also provide a great deal of new information about the chemokine receptors and adhesion molecules expressed by CTCL cells and by the PBL and TIL of patients undergoing immunotherapy for melanoma.